Coffee maker



Dec. 1, 1953 c. J. FORSCHNER 2,660,948

COFFEE MAKER Filed Oct. 16, 1947 3 Sheets-Sheet 2 SUPPZ V BY G45 sumr ATIDE/VIII? Dec. 1, 1953 Filed Oct. 16, 1947 C- J. FORSCHNER COFFEE MAKER&

3 Sheets-Sheet 3 Patented Dec. 1, 1953 UNITED STATES PATENT OFFICECOFFEE MAKER Conrad J. Forschner, New York, N. Y. Application October16, 1947, Serial No. 780,187

Claims. (01. 99-282) My invention relates to an automatic coffeemakingmachine. Since the equipment to be discussed is as applicable to thebrewing of tea and other beverages as it is to coffee-making, theconsistent reference to coffee-making herein will be understood toinclude the brewing of other beverages, including tea.

In restaurants, lunch counters, and the like, where cofiee must bebrewed in quantities and where the person responsible for brewing thecoffee can devote only a relatively small fraction of his time andattention to brewing the coffee, it is virtually impossible for suchperson to brew the coffee uniformly, from batch to batch. Quality andtaste of the brewed coffee therefore sufier, to the impairment of thecustomers satisfaction.

It is, accordingly, an object of my invention to provide an improvedcoffee-making apparatus, particularly for the application indicated.

It is another object to provide a coffee-making apparatus that willassure a uniformly brewed product, from batch to successive batch.

- It is also an object to provide a more completely automaticcoffee-making apparatus which will require no more attention of theperson responsible for brewing the coffee than that he initiate theautomatic process.

. It is a general object to achieve the above objects with an inherentlysimple apparatus that i is not likely to get out of order and that willbe easy to clean and service.

Other objects and various further features of the invention will bepointed out or will occur to those skilled in the art from a reading ofthe following specification in conjunction with the accompanyingdrawings. In said drawings, which show for illustrative purposes only, apreferred form of the invention:

Fig. 1 is a side view of a fully assembled automatic coffee makerincorporating features of the invention;

Figure 2 is an enlarged sectional view taken substantially in the plane2-2 of Fig. 1;

Fig. 3 is another enlarged sectional view taken substantially in theplane 3 3 of Fig. 1;

, Fig. 4 is an enlarged fragmentary sectional view taken substantiallyin the plane 4-4 of Fig. :3; and

Fig. 5 is a more or less schematic view illustrating the cooperativerelationship of elements in the coffee maker of Fig. 1.

Briefly stated, my invention contemplates automatic control means for acoffee or other beverage mak r ,of t e type wherein hot water of aprescribed elevated temperature is mixed only once with the coffee orother beverage grounds (or leaves, or other dried preparation from whichthe beverage essence is to be brewed or extracted) in a suitablereceptacle, which, for purposes of present description will be called acoffee-ground receptacle, and in which it is thereupon delivered to abrewed-cofiee receptacle. The control means includes a timer forproperly coordinating the measuring of water to be ad mitted to aboiler, the admission of the measured water to the boiler, the supply ofheat to the boiler, and the enforced (as by means of a pressuredifferential) straining of brewed coffee from the ground-coffeereceptacle to the brewedcoffee receptacle. As indicated above, thepresent equipment is applicable to the brewing of tea and otherbeverages, so that the specific references 'to coffee-making will not beunderstood as limiting the usefulness of the apparatus.

In the form to be described, timing is controlled by a system ofmotor-driven cams which are ganged and which complete a full singlerevolution for one cycle of brewing. This cycle may require an elapsedtime of the order of three minutes. First cam-operated switch meansoperates a valve to dump measured water (measured during the previousbrewing cycle) from the measuring tank into the boiler, more or lessconcurrently with operation of another valve to supply heat to theboiler. Upon the attainment of sufficient pressure in the boiler, themeasured quantity of then-heated water is conducted to the ground-coffeereceptacle. After a delay period during which brewing takes place,second cam-operated switch means starts a vacuum pump to produce apartial vacuum within the brewed-coffee receptacle, so that there may bea pressure differential across the pile of coffee grounds to enforce aquick complete extraction of the brewed coffee. The second switch meansmay also control a valve to admit water in a measured quantity into themeasuring tank, for use during the next brewing cycle.

Referring to the drawings, my invention is shown in application to acoffee-making machine thus serves for the support of the ground-coffeereceptacle and for the conduction of brewed coffee from the brewingchamber in receptacle it down into the brewed-coffee receptacle H. Thetwo receptacles iii-ll may be supported generally forward of the housingl2 on a bench or table i8, and held in place by resilient holdingbrackets ll engaging the neck of receptacle ii. Convenient access maythus be had to a spigot handle l9 for drawing off brewed coffee at thespout 20, as may be required.

In the form shown, the ground-coffee receptacle iii comprises a body ofpreferably substantially constant cross-section, as provided by acylindrical wall. A ground-coffe retainer 2| is slidably insertable inthe body of receptacle ID, preferably with a close fit. In the formshown, the retainer 2! comprises an annular rim piece 22 recessed tohold a filter 23, which may be of woven meta1- fiber construction. Theupper edge of the retainer rim 22 may be conically dished so as toprovide a relatively sharp edge 24 for scraping contact with the wall ofreceptacle H), as when the retainer 2i is withdrawn by lifting thehandle 25. The upper end of the receptacle Ill preferably includes anannular gutter 26 to catch such coffee grounds as may not be scraped byedge 24 into the retainer 2i upon withdrawing the same. Thus, the gutter2i; may prevent inadvertent discharge or" coffee grounds into the brewedcoffee receptacle i i. The ground-coffee receptacle II] is shown toinclude a cover 21 to which a spray nozzle 28 is secured. The nozzle ispreferably so arranged that at least som of its jets may impinge uponthe gutter 26 and thus flush the gutter each time the spray 23 isoperated. The spray 28 is shown connected to the hot-water supply systemwithin the housing 12 by means of a flexible connecting hose 29. Whenreplacing the coffee-ground retainer 22, the cover 21 may be hung on theside of the housing 12 by resting one of the handles 35 on a suitablehook 3|, as will be clear.

A indicated generally above, my preferred brewed-coffee receptacle lincludes spigot means i--c for dispensing brewed coffee withoutinverting the receptacle II, and without requiring removal of theground-coffee receptacle It]. In the form shown, the receptacle II is ofglass and open at both upper and lower ends. At the upper end, it may besealed by means of a resilient ring or washer 32 to the cover member l1,and bayonet clips 33 may engage lugs 34 to secure the cover H onreceptacle ii. The lower end of the receptacle l is shown to besupported by an annular cushion 35 on a pedestal 36; the lower rim ofthe receptacle l l projects into an annular groove in a bottom plate 31carried by the ped estal and an annular washer 38 in th same grooveserves to effect a seal between the receptacle l l and the bottom plate31', as will be clear.

In the form shown, an open generally radially directed trough in thebottom plate 31 serves to conduct brewed coffee to the passage All inthe spigot; and when the spigot i in the position shown in 4, thepassage 4| in the movable spigot block A 2 is positioned to pass brewedcoffee via passages 3Q- iii4l to the outlet or spout 20. In order thatthe draining of coffee via the outlet passages described may not createa partial vacuum over the brewed coffee in receptacle H, I have provideda venting system to become operative as the spigot handle i9 isoperated. In the venting system, a vent pipe 43 may be removably held inthe cover I? at one end, and it may be fitted, as at 4-4, to the spigotbody 45 at the other end. A second passage 46 in the spigot block 42referably connects the vent pipe 43 to the at mosphere, as via a passage41, when the block 42 is in position to drain brewed coffee through thespout 28. When coffee is not being drained, the venting system (that is,passage 43) is closed off, as will be clear.

Within the housing I2 th hot-water heating system may be generallysimilar to that which has been described in my Patent 2,210,126, issuedAugust 15, 1940. Such a heating system preferably includes a boiler l3having a plurality of heating tubes 48 for the efficient transfer of theheat provided by a gas burner 49. A solenoidoperated valve 5!} maycontrol the operation of gas burner 49, and a pilot 5! may assume normalautomatic gas-burner operation upon operation of solenoid valve 59. Ariser tube 52 is shown to connect the flexible hose 29 to the inside ofboiler is, and the bottom end of the r ser pipe 52 is preferably spacedfrom the bottom of boiler I3 by an amount which will assure a watersafety level 53 in the boiler l3. As in the case of my aforementionedpatent, reducing valve means 55 may be included in the water-supply lineas a means for automatically metering the supply of water to tank M inaccordance with the selected manual adjustment of the valve 55.

The measuring tank I4 is preferably positioned above the boiler l3, anda three-way valve 54 is of the three position variety, to be operated bytwo solenoids Eli-51. When neither of the solenoids 565l is energized,opposed compression springs 58 serve to position the valve 54 centrally,so as to block oif all inlet and outlet passages. When solenoid 51 isenergized, the tank I4 is connected to dump water into boiler 13, andwhen solenoid 55 is energized supply water is connected to the tank I4,as will be clear.

In order to control the brewing of coffee in the described apparatus, Iemploy timing means operated by an electric motor 59, which may be aclock motor. The motor 59 preferably provides a relatively slow drive toa shaft 60, as through reduction gearing 5|, and, in the form shown. thedrive shaft 611 is connected to one side of a one-way-engaging clutch62. On the other side of th one-way clutch B2, timing cam means 63-5 i55are ganged to coordinate the operation of cam-follower switch means66--61B8. A hand set or manual control knob 69 is attached to the frontend of the camshaft.

In the relationship shown in Fig. 5, none of the switches 656'!'S8 isoperated, and the apparatus is, therefore, shut down. It will beunderstood, however, that from a previous cycle of operation,'themeasuring tank M has been filled with a proper supply of water,depending upon the number of cups of coffee which the machine is to brewin one brewing cycle. The brewing cycle is initiated by a slightcounterclockwise manual rotation of the knob 35, and such slightrotation will be understood to raise the cam. follower it of switchmeans 61, so as to close the motor circuit and to commence electricdrive of the camshaft. The cam 64 is high substantially all the wayaround, with the exception of a dip H which serves to shut off the motor59 upon completion of a brewing cycle.

Concurrently with operation of switch means 6?, cam 53 may be effectiveto raise the cam follower '52 for closing switch means 66. In the formshown, one of the switches of switch means 66 is connected to operatesolenoid 51 and thus to dump measured water from tank I4 into "the thesupply of gas for theburner 49'. The heat' ing efficiency of burner '45for the boiler I3 is ceptacle I0. In order to prevent premature dis--charge of hot water or,,s tated in other words, in order better tocontrol the temperature at which hot water will be passed tothe sprayhead 28;1'

provide bleed means 15 in the riser pipe 52, preferably well above anyliquid level anticipated for the boiler I3. It will be appreciated thatthe bleed means 15 may serve to dissipate any choking efiects, and toassure that water will rise in the tube 52 for conduct to the spray head28 only I upon attainment of the desired hot-water temperature, which ispreferably less than boiling temperature. g i i 'It is not critical howlong the switch means 65 remains'operative, as long as the tank It mayfully drain, and as long as the hot water. is allowed rise in the tube29. After the hot water has forced itself out of the boiler I3, theheater 45 may continue to heat the remaining safety water until highertemperatures are reached, and I employ a thermostatic switch 15 in theboiler l3 to deenergize the solenoid of valve 59 upon attainment of atemperature in boiler I3 slightly in excess of that which .is requiredto expel the brewing water from boiler I3.

Once coffee has been'sprayed into the groundcofi'ee receptacle Ill, the'cofieegrounds will be stirred up and suspended in a brewing mixturewithinth'e receptacle ID; This brewing may be allowed to proceed (at atemperature preferably less than that of boiling water) for a relativelyextended period of time, say a minute and a half. The brewing cycle maythen be completed upon operation of switch means 68, as its cam followerH rides upon the high points of cam 65. One of the switches of switchmeans 68 is shown connected to operate a motor 18 for a vacuum pump 19,and the pump 19 is connected, as by a pipe 80, to the cap I! at the topof the brewed-coffee receptacle II. It will be clear that the functionof pump 19 is to impress a pressure differential across the filter 23and the coffee grounds, so as to enforce drainage of brewed coffee intothe brewed-coffee receptacle II. Concurrently with the operation of thevacuum pump 19, the other switch of switch means 68 may be connected tooperate solenoid 56 so that a fresh supply of metered water may fill thetank I4. By this time the low point on cam 64 may have advanced to dropthe cam follower 1c and thus to shut off the motor 59.

It will be clear that I have described a relatively simple completelyautomatic coffee-maker that may eliminate guesswork, and hence the humanelement, as a cause of inconsistent brewing. If the brewed-coffeereceptacle is relatively large, the arrangement is such that a number ofsuccessively brewed batches of coffee may be accumulated in thereceptacle II, without requiring removal of the ground -coffeereceptacle. Coffee may thus be made in quantity just before ananticipated rush-hour demand, and further coffee may be prepared evenwhile cups are served "at the spigot I9." Of course, the spigot shouldnot be operated while the vacuum process is going on, but this is amatter of relatively short time and a warning light 8! in the circuit ofmotor 18 and on the front of the housing I2 may help prevent inadvertentspigot operation at such time. If desired, unconsumed brewed coffee maybe kept hot and in best serving condition, as by means of an electrichot-plate element '82 as'regulated by thermostat switch means having anelement 83 projecting into the receptacle II. i

Although I have described a particular automatie coffee-brewing cycle,it will be clear that certain changes in timing may be made as desired.For example, if it should be preferred to have the boiler I3 full (witha measured supply of water) as soon as valve 59 is operated to applyheat, then the dumping of water from measuring tank I4 to boiler i3could take place while vacuum pump 19 is forcibly straining the brewedcoffee. In such event, the electric connections to solenoid 56 need onlybe interchanged with those for solenoid 51; cam 53 would then operatesolenoidiil to fill tank It while heat is supplied to boiler I3, and cam65 would operate solenoid 5'! to dump the measured water into boiler I3while the vacuum pump 19 is being driven, as will be clear.

While I have described my invention in detail for the preferred formshown, it will be understood that modifications may be made within thescope of'the invention as defined in the claims which follow. a

Iclaim:

1. In a brewing device of the character indicated, a brewing chamber, abrewed-beverage chamber, a water heater separate from said chambers andincluding a vessel and heating means therefor, said heating meansincluding a control element therefor, a discharge connection from saidvessel to said ibrewing chamber, the discharge capacity of said vesselbeing no greater than the capacity of said brewing chamber, areplacement-water measuring tank including valve means with connectionsto said measuring tank and to said vessel and to replacement-watersupply means; said valve means in a first relationship connecting saidmeasuring tank to said vessel, said valve means in a second relationshipconnecting said measuring tank for the supply of replacement waterthereto, and said valve means in a third relationship effectivelycutting off both said connections; first solenoid-controlled actuatingmeans in actuating relation with said valve means for actuating saidvalve means between said first and third relationships, secondsolenoid-controlled actuating means in actuating relation with saidvalve means for actuating said valve means between said second and thirdrelationships, said first solenoid-controlled actuating means beingelectrically actuable from a first position to a second position andmeans for moving the same back to said first position, said secondsolenoid-controlled actuating means being similarly actuable from and tofirst and second positions thereof, said first solenoid-controlledactuating means in said first position thereof actuating said controlelement for admitting heat to said vessel and actuating said valve meansto admit water from said measuring tank to said vessel, said firstsolenoid-controlled actuating valve means to shut off the Water supplyto said vessel; and electric-timer switch means connected to operatesaid first solenoid-controlled actuating means in a predeterminedcyclical sequence and to operate said second solenoid-controlledactuating means in another sequence having the same cyclic period assaid first sequence.

2. A brewing device according to claim 1, and including vacuum-inducingmeans connected to said brewed beverage chamber, and solenoidcontrolledactuating means for said vacuuminducing means, said last-mentionedsolenoidcontrolled actuating means being connected for controlledoperation by said timer-switch means and in a sequence involvingadmission of heat to said water heater prior to operation of saidvacuumdnducing means.

3. A brewing device according to claim 2, in which said sequenceinvolves the complete admission of heat to said heater prior tooperation of said vacuum-inducing means.

4. A brewing device according to claim 2, in which said sequenceinvolves the complete admission of heat to said heater a substantialtime interval prior to operation of said vacuum-inducing means.

5. In a brewing device of the character indicated, a brewing chamber, abrewed-beverage chamber, a water heater separate from said chambers andincluding a vessel and heating means therefor, said heating meansincluding a control element therefor, a discharge connection from saidvessel to said brewing chamber, the discharge capacity of said vesselbeing no greater than the capacity of said brewing chamber, areplacement-water measuring tank including valve means with connectionsto said measuring tank and to said vessel and to replacement-watersupply means; said valve means in a first relationship connecting saidmeasuring tank to said vessel, said valve means in a second relationshipconnecting said measuring tank for the supply of replacement waterthereto, and said valve means in a third relationship efiectivelycutting ofi both said connections; first solenoid-controlled actuatingmeans in actuating relation with said valve means for actuating saidvalve 8 means between said first and third relationships, secondsolenoid-controlled actuating means in actuating relation with saidvalve means for actuating said valve means between said second and thirdrelationships, said first solenoid-controlled actuating means in saidfirst position thereof actuating said control element for admitting heatto said vessel and actuating said valve means to shut off the watersupply to said vessel, said first solenoid-controlled actuating means insaid second position thereof actuating said control element forcontrolling the shut-ofi of heat to said heating means and actuatingsaid valve means to admit water from said measuring tank to said vessel;and electric-timer switch means connected to operate said firstsolenoid-controlled actuating means in a predetermined cyclical sequenceand to operate said second solenoid-controlled actuating means inanother sequence having the same cyclic period as said first sequence.

CONRAD J. FORSCHNER.

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